How do you properly align refference images
It really seems like the blueprints aren't very precise, as moonboots already mentioned.
Look:

I've used basic geometry as a guide and marked just two regions which should line up, but don't. The lower right part of the hood (where your active vertex resides) is clearly to high in front view (marked yellow).
In general, it is good practice to evaluate blueprints by doing this before you start.
Here are some rough steps to follow.

Research real world dimensions of your vehicle.
Create a simple box with those dimensions as reference.
Place the blueprints inside the box and make sure they match exactly on the bounds. (Roof, tires, side mirrors, trunk, front)
Check prominent features for alignment. I.e. by using more basic geometry.

That way, you can be aware of any issues right from the start.
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Blueprints are very often not exact and it won't be possible to place geometry perfectly in all views.
When that happens, you can for example stick to those views that match and work with a bit of offset on the one that doesn't match. Or you can go half way.
Just maintain the shape / curvature of the misaligned view as a reference.
And you should always find good real world reference images to decide on how to proceed with areas where the blueprints are off or don't show enough detail.
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So, as far as I can see from your blendfile, you've done nothing wrong with the blueprints.